SW1(config)#Vlan 22 SW1(config-vlan)#exit
Let’s configure another sub-interface for VLAN 22:
On R2
R2(config)#Int F0/0.22
R2(config-subif)#Encap dot1q 22
R2(config-subif)#Ip addr 22.1.1.2 255.255.255.0
On BB2
BB2(config)#Int F0/0 BB2(config-if)#No shut BB2(config)#Int F0/0.22
BB2(config-subif)#Encap dot1q 22
BB2(config-subif)#Ip addr 22.1.1.22 255.255.255.0
To verify the configuration:
On R2
R2#Ping 22.1.1.22
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 22.1.1.22, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 1/1/4 ms Before going further into the configuration of this topology, let’s summarize what we have covered in this lab:
When configuring routers in a VLAN we MUST pay attention to the following:
If the router’s interface is in ONE VLAN, then, configure the VLAN on the switch and place the interface to which the router is connected to in that VLAN.
If the router’s interface is configured in multiple VLANs, then configure the interface of the router as a trunk. ISL encapsulation is only available on the older IOS and routers, therefore the ONLY
encapsulation is DOT1q, and this means we configure multiple interfaces on the router. Each sub-interface should be configured in the appropriate VLAN as identified in the topology. The switchport to which the router is connected to, must also be configured as a trunk, YOU MUST ENSURE THAT THE VLAN IS CONFIGURED AND IT IS ALLOWED TO TRAVERSE THROUGH THE TRUNK.
Let’s configure VLAN 45. R4 needs another sub-interface configuration; R5’s F0/1 interface must be configured as trunk because it is in two different VLANs, and the F0/5 interface of SW2 should also be configured as a trunk and VLAN 45 MUST be configured/created on SW2.
On SW2
SW2(config)#Int F0/5
SW2(config-if)#Swi trunk encap dot1q SW2(config-if)#Swi mode trunk
SW2(config-if)#No shut SW2(config)#Vlan 45 SW2(config-vlan)#exit
On R4
R4(config)#Int F0/1.45
R4(config-subif)#encap dot1q 45
R4(config-subif)#Ip addr 45.1.1.4 255.255.255.0
On R5
R5(config)#Int F0/1 R5(config-if)#No shut R5(config)#Int F0/1.45
R5(config-subif)#Encap dot1q 45
R5(config-subif)#Ip addr 45.1.1.5 255.255.255.0
To verify the configuration:
On R4
R4#Ping 45.1.1.5
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 45.1.1.5, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 1/1/4 ms Let’s configure VLAN 123. We know that the following must be configured:
The F0/0 interface of BB3 must be configured in VLAN 123
The F0/13 interface of SW1 must be configured in VLAN 123, this is the interface that BB3’s F0/0 interface is connected to
BB1’s F0/0 must be configured as a trunk, since it is a member of multiple VLANs, VLAN 123, and VLAN 16.
The interface of the switch to which BB1 is connected to must also be configured as a trunk.
Another sub-interface must be configured on BB2.
On SW1
SW1(config)#Int F0/13
SW1(config-if)#Swi mode acc SW1(config-if)#Swi acc vlan 123 SW1(config-if)#No shut
On BB3
BB3(config)#Int F0/0
BB3(config-if)#Ip addr 123.1.1.33 255.255.255.0 BB3(config-if)#No shut
On BB1
BB1(config)#Int F0/0 BB1(config-if)#No shut
BB1(config-if)#Int F0/0.123
BB1(config-subif)#Encap dot1q 123
BB1(config-subif)#Ip addr 123.1.1.11 255.255.255.0
On SW1
SW1(config)#Int F0/11
SW1(config-if)#Swi tru encap dot1q SW1(config-if)#Swi mode trunk
SW1(config-if)#No shu
On BB2
BB2(config)#Int F0/0.123
BB2(config-subif)#Encap dot1q 123
BB2(config-subif)#Ip addr 123.1.1.22 255.255.255.0
To verify the configuration:
On BB2
BB2#Ping 123.1.1.11
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 123.1.1.11, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 1/1/4 ms
BB2#Ping 123.1.1.33
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 123.1.1.33, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 1/2/4 ms
The second to last VLAN is VLAN 16. To configure this VLAN we must configure the following:
The F0/0 interface of R6 should be configured as a trunk, because it is connected to two different VLANs, VLAN 16 and VLAN 56.
The F0/6 interface of SW1 must be configured as a trunk; this is the interface to which R6’s F0/0 interface is connected to.
VLAN 16 must be configured on this switch.
Another sub-interface must be configured on BB1 for this VLAN.
On R6
R6(config)#Int F0/0 R6(config-if)#No shut R6(config)#Int F0/0.16
R6(config-subif)#Encap dot1q 16
R6(config-subif)#Ip addr 16.1.1.6 255.255.255.0
On SW1
SW1(config)#Int F0/6
SW1(config-if)#Swi trunk encap dot1q SW1(config-if)#Swi mode trunk
SW1(config-if)#No shut SW1(config)#VLAN 16 SW1(config-vlan)#Exit
On BB1
BB1(config)#Int F0/0.16
BB1(config-subif)#Encap dot1q 16
BB1(config-subif)#Ip addr 16.1.1.11 255.255.255.0
To verify the configuration:
On BB1
BB1#Ping 16.1.1.6
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 16.1.1.6, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 1/1/4 ms NOW……the last VLAN in this topology, VLAN 56.
In this case we can see that R5 is using its F0/1 and R6 is using its F0/0 interface, this means that they are connected to two different switches. This means that a trunk must be configured to connect these two switches and the trunk must allow the VLAN to traverse through this trunk link.
A sub-interface must be configured on R5 for this VLAN
A sub-interface must be configured on R6 for this VLAN
VLAN 56 must be configured on BOTH SWITCHES, or VTP messages must be configured to propagate the VLAN.
On SW1
SW1(config)#Vlan 56 SW1(config-vlan)#exit
On SW2
SW2(config)#Vlan 56 SW2(config-vlan)#exit
To configure a trunk link between the switches:
On SW1 and SW2
SWx(config)#Int F0/18
SWx(config-if)#Swi tru enc dot SWx(config-if)#Swi mode trunk SWx(config-if)#No shu
On R5
R5(config)#Int F0/1.56
R5(config-subif)#Encap dot 56
R5(config-subif)#Ip addr 56.1.1.5 255.255.255.0
On R6
R6(config)#Int F0/0.56
R6(config-subif)#Encap dot 56
R6(config-subif)#Ip addr 56.1.1.6 255.255.255.0